PHP/DNS/gethostbyaddr
Determining the Hostname of a Remote IP
<?php
$hostname = gethostbyaddr($_SERVER["REMOTE_ADDR"]);
if($hostname === $_SERVER["REMOTE_ADDR"]) {
echo "The host name could not be resolved.<BR/>\n";
} else {
echo "The host name is: $hostname<BR/>\n";
}
?>
Using gethostbyaddr() to Get a Hostname
<html>
<head>
<title>Using gethostbyaddr() to get a host name</title>
</head>
<body>
<div>
<?php
if ( ! empty( $_SERVER["REMOTE_HOST"] ) ) {
print "Hello visitor at ".$_SERVER["REMOTE_HOST"];
} else if ( ! empty( $_SERVER["REMOTE_ADDR"] ) ) {
print "Hello visitor at ";
print gethostbyaddr( $_SERVER["REMOTE_ADDR"] );
} else {
print "Hello you, wherever you are";
}
?>
</div>
</body>
</html>